In general, a construction machine (construction vehicle) is used for civil-engineering work or construction work, and requires large power for an operation, so that a vehicle using hydraulic pressure is used. The kind of hydraulic work vehicle includes a wheel loader, an excavator, a grader, a crane, a conveying machine, and the like.
The wheel loader is a work vehicle used for digging up and moving earth and sand, aggregate, and the like in a civil-engineering work field. The wheel loader is dedicated equipment for repeatedly performing an operation of putting a workpiece into a front work machine (for example, a bucket of the wheel loader) according to an operation of a joystick by an operator while moving toward the workpiece (for example, earth and sand), moving to a truck or a target location, and dumping the workpiece of the work machine to a loading location.
FIG. 1 is a diagram illustrating a wheel loader in the related art.
In general, in the wheel loader, a work machine is operated through a joystick. That is, a driver may operate the work machine by raising and floating a boom 1 while seated in a cabin 3, and further, may operate the work machine by crowding and dumping a bucket 2.
FIG. 2 is a diagram illustrating an operation range of a boom and a bucket of a general wheel loader.
FIG. 2 illustrates a case where a boom 1 is at a raised position and a floated position, and a bucket 2 of the wheel loader is at a crowd position (that is, the bucket has an angle b in FIG. 2) and a dump position (that is, the bucket has an angle a in FIG. 2) at each position of the boom 1.
When work is performed by using the wheel loader, the boom 1 and the bucket 2 of the wheel loader are operated through a joystick of a main control valve (MCV), and further, a driver may move the wheel loader forwardly and backwardly by using a travelling device of the wheel loader during the operation. In general, the driver moves the wheel loader forwardly by using the travelling device, and raises and floats the boom 1 of the wheel loader and/or crowds and dumps the bucket 2 by operating the joystick. Particularly, there are many cases where the wheel loader changes a travelling direction from forward to backward or from backward to forward during the operation, and simultaneously operates the work machine (for example, the boom and the bucket of the wheel loader).